1. Field of the Invention
This invention relates to devices for delivering flowable material and more particularly concerns devices for delivering flowable material from an underground borehold.
2. Description of Prior Art
U.S. Pat. No. 4,386,654 to Becker describes a downhole pump for delivering flowable material which comprises a helical screw type rotor mounted within a resilient stator. The pump is connected to drive means which also comprises a helical screw type rotor mounted within a resilient stator, the rotor being driven by pressurised oil delivered from the ground surface. The drive means is connected to the pump by drive transmission means including universal joints and a drive shaft.
An object of the present invention is to provide a device for delivering flowable material from an underground borehole which is simpler in construction and relatively easy to manufacture.
Another object of the present invention is to provide a device of the above type which is more reliable and able to withstand better the extreme operating conditions often present in a production borehole.